This invention relates to a foldable or "collapsible" ladder. In general, emergency ladders of the types used in fire escapes are rather bulky or do not provide the stability of steps and side rails present in conventional ladders. Moreover, such ladders are not always readily transformed from a storage or folded condition to an extended or use condition.
As a result, foldable or collapsible ladders are known. Such ladders comprise segments which fold flat against each other when not in use, and which assume a three-dimensional form when extended for use.
What is needed is a collapsible ladder which comprises segments which fold flat against each other when in storage, which are easily manufactured and which provide the structures required to cause the side elements in each segment to be held in the proper relative position, and which provides the required overall strength.